Update submodules: plugins (new commits)

plugins:
    edc2349 Chris Smith <chris@dmdirc.com>
            Remove DialogManager.

            Replace remaining legitimate usages with [Keyed]DialogProviders.

            Remove the DialogManager itself, all the getters for it, all the places keeping
            references around to it, all the dialogs taking it in the constructor, and all
            the partridges in pear trees that had one hidden away.

            Gerrit: http://gerrit.dmdirc.com/3048

Change-Id: I874f4bff3b5b567e9ec42a3e3324e052a885efff